Yes, definitely look in the nooks and crannies! My first layer was laying in a thorn patch. Wyandottes and Australorps, at least mine, tend to be a little slower maturing.
ploub and hilaryhake - Hope your girls lay soon! It is always so hard. What type of chickens do you have ploub?
HilaryHake- It sounds like you take such good care of your babies! I bet they're spoiled rotten. :)